Was there Really an Adam and Eve?

I have a theory which I developed in 1987, which is that the entire human race today is descended from one man and one woman who lived somewhere around 150,000 to 200,000 years ago.

I base my theory entirely on mathematics and probability and statistics. I wrote a few essays on this back in 1987 and 1988. There was no Internet back then and they were never published.

I am thinking of typing my calculations and posting them.

Here are the general outlines of my theory: (I think it is fair to call it "my theory" because I have never heard or read anybody else express my point of view. Others have reached a conclusion similar to mine, but they have followed a different route. Their theories are based on DNA studies. Mine is not.)

We know that humans have lived on this earth for about three million years. The most famous example of the earliest women was "Lucy", who lived three million years ago. Although different from modern humans, she was enough like us that if we saw her walking down the street today, we would know that she was one of us and not just a monkey or an ape.

However, even though there were people who lived three million years ago, almost all of their family lines eventually died out. Only one family survived, and every man, woman and child who is alive today, whether they be white, black, pink, purple or polka-dot, are all descended from that one family, which originally consisted of just two people.

I believe that I can prove this by simple math. These calculations have nothing to do with Adam, Eve, Noah and his Ark or any type or variety of religion. The conclusion is reached by simple math.

There are several ways to prove this: from the front and from the back. Let's start from the front first:

We all have two parents, four grandparents, eight grandparents and, unless a bit of incest has crept in, 16 great grandparents.

If we go back 10 generations, we all have 1024 great-great-great-great-great-great-great-great-grandparents. For ease of calculations, we will round that number down to an even thousand.

Since it is a reasonable assumption that a generation lasts 30 years, this means that 300 years ago in the year 1699, about one thousand of our ancestors were alive.

If we continue this back another ten generations, we find that in the year 1399 we had a million ancestors who were alive.

Going back still another ten generations, we can say that we had a billion ancestors who were alive in the year 1099 AD.

Since we know that we did not have a billion ancestors 900 years ago, we know that there was some degree of what might be called incest. If we could make a complete list of our ancestors 30 generations back, we would find the same names over and over again on the list. Also, in view of the lack of modern transportation and communication back them, many people lived and died within a few miles of their place of birth, so there must have been a lot of what we would call intermarriage.

In short, it might turn out that a complete list of our actual ancestors 30 generations back might be a small number, less than a hundred thousand.

However, 30 generations back is not ancient history. Those were modern times. Humans have lived for three million years, which is approximately one hundred thousand generations.

As we go back more than 30 generations, we should find that the number of our ancestors, rather than increase, decreases. The further we go back, the less ancestors we have until it may be that the actual number we reach is two (Adam and Eve?).

Now, let's come from the other direction. Remember I am not claiming that there were only two people alive at the time of this Adam and Eve. There were many people, perhaps a few hundred thousand alive, but according to the laws of probabilities, only the descendants of two survived.

A population explosion occurred 10,000 years ago after the end of the last Ice Age when farming was developed. With farming, humans had a stable food supply and did not have to go out chasing animals to get something to eat.

Before farming, the world population is believed to have been about 200,000. In my theory, it does not really matter what the number was, the result comes out to be about the same. However, what is important is that in general the population remained stable. In other words, for a million years more or less the world population was about 200,000 people. The population did not increase or decrease much.

To make it as easy as possible to understand my theory, I will postulate that there were only eight people alive: four men and four women. Since the population did not change from one generation to the next, we will assume that every member of the population exactly reproduced itself. Each person had two children, who made two more children. (If a woman had ten children, it did not matter if eight died and never reproduced, as long as only two of her children had children, which was the case on average).

The reason I picked the number 8 is that this is the lowest number which shows my point.

Let's assume that the four men were named Al, Bill, Charles and Dave. The rule is, each time they have a son, they give their name to their son. The girls are not important in this calculation.

Since there are an even number of boys and girls (remember we are making an idealized example) among these four men, one produces two boys, one produces two girls and the remaining two produce one boy and one girl each.

We will assume that Al has two boys, Bill and Charles have one boy and one girl and Dave has two girls.

In the second generation, two boys will be named Al, one boy will be named Bill, one boy will be named Charles and nobody will be named Dave. The family line of Dave will have dropped out, because he only only girls.

Continuing this process, in the third generation there will be two main possibilities. Either three boys will be named Al and one boy will be named Bill or two boys will be named Al and two boys will be named Bill. There will be nobody named Charles left.

Work this out. It is possible that three names could survive into the third generation. For example, in the second generation, the first Al could have one son, while the second Al has no sons, Bill has one son and Charles has two sons. This would leave two boys named Charles, one Al and one Bill. However, the odds are that after three generations, only two names will be left. If three names do manage to survive to the third generation, one will probably be wiped out in the following generation or if not, then in the next or the next and so on. Remember that humans have lived for one hundred thousand generations.

Now, instead of starting with only 8 people alive on the Earth, we will say that there were 16 people, 8 men and 8 women, and repeat the process. This time, the men are named Al, Bill, Charles, Dave, Ed, Frank, George and Henry. Again, each one has two children.

So, in the next generation, two boys will be named Al and Bill each, one boy will be named Charles, Dave, Ed and Frank and nobody will be named George or Henry.

In the following generation, there are many possibilities, but a likely one is that there will be three named Al, three named Bill, one named Charles and one named Dave. Ed and Frank will have been wiped out.

After one or two generations more there will be five named Al, three named Bill and both Charles and Dave will be extinct.

After two or three generations more, all eight boys will be named Al or possibly Bill and the other names will have vanished.

Even with a small population of eight males, the probabilities are difficult to work out in the head, but it should be readily apparent that with a small population of only 8 males and 8 females, all but one male name will become extinct within 7 or 8 generations, and in any case less than ten generations.

Actually, I could just about figure out in my head how many generations it would take for all the names to be reduced to one, if the population was only 16. However, if the population were doubled to 32 (16 males and 16 females) it would take a computer program to figure it out.

My point is that even without a computer program, we still know the result. Even though there are 16 names to start with, after a certain number of generations, perhaps 20, there will be only one family name left.

So, what happens if the number is much larger? Let us say that there were 256,000 males, each with a different name.

The math works out that after the first generation, 25% or 64,000 names disappear. After the second generation, 36,000 more names will disappear. However, just as Al got off to a big head start when there were only four males, if there are 256,000 males, then after three generations 15 males will have eight sons each and about 500 males will have 7 sons each whereas 23,764 more will have become extinct, for a total of 123,764 extinct. Therefore, after three generations, almost half of the family names will have become extinct.

From then on, it will be seen that with every new generation, more family names die out. The process is inevitable and it can be said with certainty that at some point there will be only one family left. All of the other families will have died out.

How long will this take? Back in 1988, I calculated that this would happen after about 150,000 to 200,000 years, which would be between 5,000 and 6667 generations.

This is why I said that the proof that all humans alive today have only one type of mitochondrial DNA proves nothing about human history, because it can be calculated that after that many generations only one type would survive anyway.

However, remember that my theory goes even further than this. I am saying that if each of us had the ability to calculate our father's father's father's father's father's and so on back to the beginning of the human race, we will reach a point where all of us have the same father. I realize that some of you white people will find it objectionable to hear that you might be brothers with the black people across the street, but the laws of probability show that we are all brothers if you go back far enough, and you do not have to go back to the beginning of the human race. You only have to go back at the very most to no more than 200,000 years ago.

I believe that the real number is much less than 200,000 years. My opinion is that the actual number is 100,000 to 150,000 years before we find our "Adam", and it might even be a much smaller number, less than 50,000 years, which brings us to about the time that the Neanderthal man started to die out.

This coincides with another subject. The Neanderthal Man lived only in Europe and died out 35,000 years ago. Northern Europeans have a characteristic which no other race or group has, which is blond hair and blue or green eyes (which my own family has, incidentally). Because of this, many have suggested that the Neanderthal men did not completely die out, but that their DNA survives in these blond haired, blue eyed people today.

However, my theory excludes this possibility. Under my theory, all of us are descended from one man. If true, it is obvious that that one man lived in Africa.

So my theory is that the Neanderthals all died out and none of their DNA survives in any human alive today. This matter is still being debated in scientific publications, but I believe that my point of view is prevailing.

Next, by the same process of finding that we are all descended from one man, we also find out that we are all descended from one woman. The question is: Did that one man and one woman know each other? Did they mate? Or, did they live thousands of years and thousands of miles apart?

The reason I feel that not only will we find an "Adam" and an "Eve", but we will find that they were "married" to each other is as follows: We go back 100,000 or so years and find one man who is the father of us all. However, he had a father and his father had a father and so on, and all of these father's father's father's are the fathers of us all.

On the female side, the same thing happens. The first woman who was the mother of us all let us say lived 80,000 years ago, but she had a mother who had a mother who had a mother and so on back.

So, at some point, it was inevitable that somewhere along the line the father's father's father would meet the mother's mother's mother and hit it off just fine and there we have our Adam and Eve.

This probably of this is increased by the fact that all of mankind originally lived in the vicinity of the Great Rift in Africa. Later on, they spread out, but for the first couple of million years they all lived near the Great Rift. Our common ancestors will not be found in Europe or Asia. They will be found somewhere around the Great Rift, and at some point it is probable that they must have known each other.

Finally, the model I have created above, where every man and every woman has exactly two children, is not realistic. In reality, some men and some women had ten children. Many, perhaps a majority, had zero children. Still, in the end, the population remained stable. If somebody could run a computer program based on reasonable assumptions about how many had ten children, how many had nine and so on, it is obvious the number of generations required to find the one mother of us all is less than the number of generations required if every woman has exactly two children.

The same logic follows for the men. As a side subject, I have been wondering whether the most reproductive stone age men had more children than the most reproductive stone age women. I believe that men having a large number of children is a modern phenomena. A man if he is rich enough, can have as many women as he wants. A few kings and sultans within modern history have had hundreds of children. Back before there was money, you could not so easily buy a woman, so to get one you had to bash another cave man over his head. A man could do this once or twice, but before long another man would bash him over the head. So, my opinion is that not many men had a large number of children. However, I am just guessing and this is not important to my thesis.

Finally, in addition to the fact that some men and women had many children while others had few or none, there were undoubtedly periods when the human population dropped drastically due to famine or disease. It is obviously more likely that our Adam and Eve came from a period when the human population was low, but this is not important to my thesis.

Here is a quotation I have taken from another source:

"1. About 150,000 years ago by best estimates and based on a "global" sample of human mitochondrial DNA sequences and a whole heap of assumptions about rates of change, species Homo Heidelbergensis collapsed in size to a few hundred individuals.

"2. As we know in small populations a genetic change can have a faster effect on the overall genetic profile of that population. Imagine a ripple in a small pool as opposed to a VERY big pool.

"3. One woman 'African Eve' had a genetic profile which was more "coherent" and gave her a reproductive advantage over all other human females, all whom eventually left no direct female descendants.

"4. In other words, in matrilineal terms, we all are descendants of African Eve."

However, you can see that my theory does not depend on these factors. Under my theory, the entire human population could remain stable at about 200,000 people throughout the human existence and there would still be somewhere back there one "Adam" and one "Eve".

The fact that there is also an "Adam" and an "Eve" in the Bible would not be a coincidence. The same math which I have just done could easily have been done by thinkers three thousand years ago and by the same logic they would have concluded that there must have been a man and a woman who were the parents of us all.

Also, my theory does not require this Eve to have a reproductive advantage over other women. It could have been luck as by flipping a coin that her children turned out to have the genes that survived. One way to prove the correctness of my theory would be to flip a coin a few million times. Nevertheless, we are not all created equal and the fact that some people have advantages over others shortens the length of time we have to go back to find the Eve who was the mother of us all.

Sam Sloan

Commentary:

There is a serious mathematical error in your essay. You make a plausible argument that there was one couple such that the man is everybody's father's father's father's....father and the woman is everybody's mother's mother's mother's ... mother. (There are some gaps in the argument which make it less than conclusive, but it is certainly very possible.) But all this means is that if you take the lineage of everyone today in the direct male line or the direct female line, you will end up with their family. It does NOT mean that other people who were around at the time didn't contribute, just that any lineage from those people that survives today involved an alternation between male and female at some point.

Adam and Eve have George, Helen, Irving, and Julia; Bob and Carol have Karl and Laura; Dave and Francine have Maureen and Norm.

In the next generation George marries Laura and they have Oscar and Pete; Irving marries Francine and they have Quincy and Roger; Helen marries Norm and they have Sally and Tina; and Julia marries Karl and they have Uma and Vicki.

There are 8 people in the third generation. They all have Adam as their father's father and Eve as their mother's mother, but also two other grandparents (Bob and Carol, or Dave and Francine). From then on, everyone's father's father's...father will be Adam and everyone's mother's mother's .... mother will be Eve, but Adam and Eve each contributed 25% to the total gene pool and their 4 contemporaries each contributed 12.5%.

-- Joe Shipman ( shipman@savera.com )

Dear Joe,

I got it now.

All the boys in the third generation have Adam as their father's father, while all the girls in the third generation have Eve as their mother's mother.

So, you are correct that I have made a mistake. I will have to think about this and see if I can find a way to salvage it.

I am going to add your simple example to my web site if you do not mind.

A number of genetic reasons have been offered proving that my original thesis is impossible but your addition that some of the genes must have come from outside the original family actually patches a hole in my theory.

Sam

OK. There is a slight inaccuracy below -- where I wrote "They all have Adam as their father's father and Eve as their mother's mother, but also two other grandparents" I should have written "The boys all have Adam as their father's father, and the girls all have Eve as their mother's mother, but all have two other grandparents".

The theory this supports is that Adam and Eve are everyone's ancestors, but other people around at the time also have descendants today; the Bible actually seems to imply this in preference to the theory that the children of Adam and Eve only married each other. When God intervened in the lives of Adam and Eve, it was not to create them as unborn adults, but rather to "wake them up" so they had souls in God's image rather than beastlike ones. No other theory is compatible with both the Bible and the scientific evidence.